Plant functional types define magnitude of drought response in peatland CO2 exchange

TY - JOUR

T1 - Plant functional types define magnitude of drought response in peatland CO2 exchange

AU - Kuiper, J.J.

AU - Mooij, W.M.

AU - Bragazza, L.

AU - Robroek, B.J.M.

N1 - Reporting year: 2013 Metis note: 5504; AqE Data archiving: no data; property of UU

PY - 2014

Y1 - 2014

N2 - Peatlands are important sinks for atmospheric carbon (C), yet the role of plant functional types (PFTs) for C sequestration under climatic perturbations is still unclear. A plant removal experiment was used to study the importance of vascular PFTs for the net ecosystem CO2 exchange (NEE) during (i.e. resistance) and after (i.e. recovery) an experimental drought. The removal of PFTs caused a decrease of NEE, but the rate differed between microhabitats (i.e. hummocks and lawns) and the type of PFTs. Ericoid removal had a large effect on NEE in hummocks, while in the lawns the graminoids played a major role. The removal of PFTs did not affect the resistance or the recovery after the experimental drought. We argue that the response of Sphagnum mosses (the only PFT present in all treatments) to drought is dominant over that of coexisting PFTs. However, we observed that the moment in which the system switched from C sink to C source during the drought was controlled by the vascular PFTs. In the light of climate change, the shifts in species composition or even the loss of certain PFTs are expected to strongly affect the future C dynamics in response to environmental stress.

AB - Peatlands are important sinks for atmospheric carbon (C), yet the role of plant functional types (PFTs) for C sequestration under climatic perturbations is still unclear. A plant removal experiment was used to study the importance of vascular PFTs for the net ecosystem CO2 exchange (NEE) during (i.e. resistance) and after (i.e. recovery) an experimental drought. The removal of PFTs caused a decrease of NEE, but the rate differed between microhabitats (i.e. hummocks and lawns) and the type of PFTs. Ericoid removal had a large effect on NEE in hummocks, while in the lawns the graminoids played a major role. The removal of PFTs did not affect the resistance or the recovery after the experimental drought. We argue that the response of Sphagnum mosses (the only PFT present in all treatments) to drought is dominant over that of coexisting PFTs. However, we observed that the moment in which the system switched from C sink to C source during the drought was controlled by the vascular PFTs. In the light of climate change, the shifts in species composition or even the loss of certain PFTs are expected to strongly affect the future C dynamics in response to environmental stress.

KW - international

U2 - 10.1890/13-0270.1

DO - 10.1890/13-0270.1

M3 - Article

SN - 0012-9658

VL - 95

SP - 123

EP - 131

JO - Ecology

JF - Ecology

IS - 1

ER -